In laser scanning microscope applications, live cell research plays an ever-increasing part, examples being the observation of metabolic processes in cells, or the analysis of the effect of pharmaceuticals. Besides the detection of reflected light, fluorescence microscopy is of particular importance, as it permits subcellular optical observation and can be employed not only for mere imaging but also for specimen manipulation and analysis, for which single-photon or multiphoton processes are used. Specimens can, for example, be manipulated in a defined manner at one scanning speed and observed at a second, e.g., higher scanning speed.
For such scientific applications, microscope systems must satisfy increasingly stringent requirements. On the one hand, data have to be acquired at a high speed to permit the course of biological processes to be followed in time; on the other hand, light losses in the beam paths should be avoided. This can be achieved, for example, if the beam paths between light source and detector have the least number of optical components while providing the maximum possible transmittance and resolution in the varied applications.